Opening device for sheet-metal cans and boxes



O. LARSEN. OPENING DEVICE FOR SHEET METAL CANS AND BOXES. APPLICATION FILED MAY 6. I918.

1,368,038. Patented Feb. 8, 1921.

Inventor: I]. L m: s an Edi/QM Attorney UNITED STATES PATENT OFFICE.

OLAF LARSEN, OF STAVANGER, NORWAY.

Specification of Letters Patent.

Patented Feb. 8, 1921.

Application filed May 6, 1918. Serial No. 232,857.

To all whom it may concern Be it known that I, OLAF LARSEN, citizen of Norway, residing at Stavanger, Norway,

have invented a new and useful Improvement in Opening Devices for Sheet-Metal Cans and Boxes; and I do hereby declare the following to be a full, clear, and exact description of the same.

from the remaining lid by means of the key.

To obtainsuch a double-bending it is of essential importance that only the uttermost end of the tongue is detached and bent downward. To accomplish this result, the weakening lines limiting the sides of the tongue are interrupted near the tongue end by non-weakened or only a little weakened portions, which limit the breaking-up of the tongue end, when the latter is pressed down into the box by means of the key.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a plan view of a tin, showing the arrangement of the weakening lines in the lid.

Figs. 2, 3 and 4 are sectional views on the line A-B of Fig. 1, showing difi'erent operations during the opening of the tin.

Fig. 5 shows'a form of construction of the key to be used and illustrates how it has to be attached to the opening tongue.

Fig. 6 shows another constructional form of the key.

The ordinarily arranged weakening lines -1- of the lid are interrupted by the transversal weakening line 2. The intersection-points between the lines -1 and 2 are by short weakening lines --3' I connected with a'weakening line -4- ari which the weakening is not as deep as elsewhere, or the weakening lines are totally interrupted.

The flat-iron key 6-- (Fig. 5) is provided with a slot, suitably consisting. of a narrow and a wide part 7 and -8 respectively. On each of the narrow sides, the key is provided with an offset 9, and the outer end -10 of the key projecting between these ofi'sets has a width, corresponding to the width of the opening tongue 2'. 0. equal to the length of'the weakening lines -2- and 4 between the lines The opening of the tin is carried outin the following way":

The key is placed in a vertical position with its outer edge'alongside the weakening line and firmly pressed downward (Fig. 2). Hereby the portion.5 is broken up along the weakening lines -.-3 and -4 and bent after the line 2 down into the box (Fig. 3), as the non-weakened or only a little weakened portions -3" exert a resistance and prevent any further tearing out along the lines 1. When the ofi'sets 9- of the key meet the remaining edge of the lid located along the weakening lines' 3 the intrusion of the: key into the box is upheld. Thereafter the key is swung or.

tilted in the direction of the arrow -11, whereupon firstly the .portion 5 is bent in under the tongue and then the said tongue is bent upward, during which operation the key is supported upon the folding rim of the lid (Fig. 4).

The key now is threaded upon the upwardly bent tongue, the outer bent end of which 8,, whereupon the key is thus displaced in such a manner in its longitudinal dlrection, that the tongue is passed into the narrow slot 7-- (Fig. 5). As this slot, is too narrow to allow the bent end of the tongue to slide out through it, the key hereby gets an absolutely safe hold. The further open-' ing of the tin is now accomplished in the common way, by turning the key 1n the direction of the arrow 12.

The, arrangement of the weakening lines, may be -varied without departingjronr. the main featuresof the invention. .As for nstance the weakening line -2- may be disis put through the wide slot pensed with although the resence of*th is end -14 of ,the 'key also in this case should be flat and provided with offsets, as illustrated in Fig. 5.

I claim: 1. In a can having its stationary cover provided with weakening lines outlining a removable lid and tongue and alsoprovi ed with a transverse weakening line at the juncture of the lid and tongue and parallel with the outer edge of tongue, and said weakening lines bemg interrupted by nonweakened portions at the sides of the juncture of the lid and tongue for limiting the breaking out of the tongue when the latter is depressed.

tongue struck outthere'from and having its a outer portion folded inwardly upon itself to form an abutment, of akey having. a

slot for arrangement over the inwardly folded portion so as to permit of a sliding of the key across'the ton ue, and theslot being restricted at one en so that the portions of't-he key adjacent the sides of this restricted portion will embrace the upper and lower faces of the tongue and the abutment subsequent to the sl ding of the key, substantially .as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing'witnesses.

Witnesses:

Cmus'rnm Bononn, ALF Gno. HEGE.

OLAF ARsEi 

